(2/3-1/12-4/15)×(-60).
问题描述:
(
-2 3
-1 12
)×(-60). 4 15
答
(
-2 3
-1 12
)×(-60)4 15
=
×(-60)-2 3
×(-60)-1 12
×(-60)4 15
=-40+5+16
=-40+21
=-19.